| At present,as a new trend of railway transportation in the world,high-speed railway has developed rapidly in many countries because of its safety,reliability,convenience and speed,and has gradually become a major achievement of contemporary railway technology.With the increasing speed and operating mileage of trains,higher requirements are placed on the safety and reliability of railway track equipment,especially for train’s track switching and changing.As an important part of railway turnouts,turnout switch rails are often used at the corners of train travel,and its production quality restricts the speed of trains and the safety and reliability of railway turnouts,and is the throat of train passage.In order to improve the current situation of high labor intensity and low efficiency in the current industrial turnout switch rail top bending process,this paper studies the pressure top bending process of turnout switch rail,and the main research content is as follows:(1)Using the analytical method,analyze the calculation method of elastic-plastic regional distribution law,stress and bending moment of length and section during the bending deformation of rail parts,establish the mechanical model and load-displacement mathematical model of the pressure bending process of the switch rail,and select the typical section of the switch rail to solve it,obtain the load-displacement model curve of the pressure bending process of the sharp rail under different distances,and establish the corresponding beam element model for simulation analysis.(2)According to the actual working conditions of the industrial site,the finite element simulation model of the bending process of the switch rail is established,the bending stroke solved by the theoretical model is simulated and the error analysis is carried out,the theoretical model is modified based on the simulation data,and the prediction model curve of the pressure bending stroke of the switch rail under different distances is obtained,and the curve is verified by experimental and simulation data respectively.(3)According to the characteristics of single arc of the linear large deflection plane of the curved switch rail design,a coincident equal-step segmented top bending method is proposed,that is,the curved sharp rail circular section is divided into several top bending elements to bend separately,and finally achieve the required design line type.A certain type of curved switch rail is selected for simulation analysis of different segment step lengths,the prediction model of the top bending stroke of each section of the top bending unit is established and the top bending stroke prediction is predicted,and the influence of different segment step sizes on the top bending accuracy is obtained through simulation analysis. |
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